Lubricating oil



Patented Sept. 25, 1934 Meme PATENT OFFICE tion of Delaware I No Drawing. Application November 5, 1928, Serial No. 317,483

6 Claims.

This invention relates to improvements in lubricating oils.

An object of the invention is to produce a lubricating oil from neutral stock which has a red tint with a greenish fluorescence or outer- '15 cost of production.

It has been found by experiment that color bodies can be derived froma petroleum base which may be added to neutral stock to produce the desired color characteristic and fluorescence.

The oil thus treated has a lower carbon residue than the blend of the neutral and bright stock.

It has been observed that fluorescence occurs in petroleum distillates from kerosene down to heavy lubricating distillates, usually increasing in intensity, with an increase in the specific gravity of the distillates. The increase in intensity of fiuorescence with an increase of specific gravity indicates that the substances producing the color and fluorescence are, in fact, unsaturated compounds formed by cracking during distillation, as the boiling points of distillates showing greatest fluorescence are near or above the temperature at which thermal decomposition of petroleum begins.

It has also been observed that some crude oils show a greenish fluorescence before distillation, but that after distillation the residue shows no trace of it. This is because, either the original substances are destroyed, or they are masked by the tarry material present in the residue, and it is thought that the latter is probably the true reason.

Therefore, the problem has been to separate the color bodies in such a form that they may be compounded with the neutral oil stock to produce the desired results, without changing the normal physical characteristics of the oil.

I have found, by adding the essence obtained from either of two sources, namely, a mixture of acid sludge from the treatment of neutral stock, with a cracked petroleum residue; or from the cracked petroleum residue agitated with ethyl ether or other solvents directly to the finished neutral stock, or by adding the essence to the untreated neutral stock and subjecting the mixture to a contact treatment with filter clay, that the product that results has the desired red color tint and a greenish fluorescence or outertone. If a relatively small amount of acid is added to the compound of the essence and the untreated neutral stock, the color resulting is lighter than when no acid is employed.

When obtained from the first named source, the acid sludge and cracked residue are mixed in equal parts and heated to approximately 300 Fahrenheit. This causes a separation of an oil, reddish brown in color, from the solid coke. After it is segregated, the oil is washed with water to remove any water soluble sulphonic acids and any free sulphuric acid. When obtained from the second source, the cracked residue is thoroughly agitated with ethyl ether. The extract is then separated from the coke and other insoluble bodies by filtration, and the ether evaporated therefrom, which leaves a residue containing the color material. The consistency of this residue varies from a semi-solid to a thick heavy liquid, depending upon the consistency of the residue used.

It has been found that the addition of the dye essence to the oil stock has practically no infiuence on the physical characteristics of the oil other than to impart thereto the desired color and fluorescence. The amount of added dye essence normally varies from 0.01% to 2.0% to dye the oil, so that it will have substantially the appearance of normal bright stock. The dye essence has substantially the same viscosity, flash and fire point, and therefore may be added to the oil stock without changing these characteristics.

The term cracked petroleum residue as used here, and as understood in the art, refers to a I particular product, the residue from a cracking process operating on crude petroleum or topped crude.

From the foregoing it will be understood that I have provided a product that radically differs from the known artificially colored or blended red oils, and that the product may be made economically from starting materials having a very small value and which are, in fact, practically by-products from the normal refining processes.

What I claim and desire to secure by Letters Patent is:-

1. As a new article of manufacture, a compound of neutral oil stock and a dye essence derived from a cracked petroleum residue, said compound having a red tint by transmitted light and a greenish fluorescence by reflected light.

2. A lubricating oil comprising pale oil stock tinted with a dye derived from a mixture of acid ha cc 5. The process of making lubricating oils which comprises extracting a dye essence containing color bodies from a cracked petroleum residue, and adding the same to a finished lubricating oil stock .for imparting a green fluorescence to the oil.

6. The process of making lubricating oils which comprises extracting a dye essence containing color bodies from a cracked petroleum residue,

adding the same to an unfinished lubricating oil for imparting a green fluorescence to the oil, and subjecting the mixture to a contact treatment.

FREDERICK R. LANG. 

